The role of lymphadenectomy has been controversial in urological malignancies. Urothelial carcinoma of the bladder and upper urinary tract has a high potential to spread through the lymphatic network compared with other malignancies, including renal cell carcinoma or prostate cancer. In urothelial carcinoma of the bladder, lymphadenectomy of pelvic nodes had been considered as the standard procedure when radical cystectomy was carried out. Recently, many investigators have examined the influence of its extent, and the majority of the studies have supported the beneficial role of extended lymphadenectomy in accurate staging or in improving patient survival. Although randomized controlled trials are required to establish a greater level of evidence, more urological surgeons have already noticed the necessity for extended lymphadenectomy in bladder cancer. In contrast to bladder cancer, there have been far fewer studies on urothelial carcinoma of the upper urinary tract. This might be because of the smaller number of the patients with urothelial carcinoma of the upper urinary tract and the lack of understanding of regional nodes. However, studies of lymph node mapping and the retrospective analyses with respect to the benefit of lymphadenectomy have been carried out in urothelial carcinoma of the upper urinary tract by some investigators, although the results are still controversial. However, the results from multi-institutional studies by high volume centers have supported the beneficial role of lymphadenectomy in urothelial carcinoma of the upper urinary tract, as it has been proposed in bladder cancer. Thus, lymphadenectomy for urothelial carcinoma of the bladder and the upper urinary tract might have a potential role in staging and improving the oncological outcomes.